How bad is this expansion tank location?

[john192719]

Hi,

I just recently noticed that the expansion tank in my house is installed like so

main water shutoff valve - > Pressure Reducing Valve -> expansion tank -> cold water shutoff valve to water heater -> water heater

but from everything I've read it should be

main water shutoff valve - > Pressure Reducing Valve -> cold water shutoff valve to water heater -> expansion tank -> water heater

Just how bad is it that it's not installed the latter? Is this something I should immediately fix?

Thanks everyone!